The SignalGuru app helps drivers avoid red lights, save gas.

A new system designed to reduce idling time at traffic lights could dramatically increase fuel efficiency, a study has shown.

Researchers at the Massachusetts Institute of Technology revealed a new app this week that has been used to cut wasted fuel by telling drivers how to drive 'in sync' with traffic lights.

The SignalGuru smartphone software uses GPS and visual data captured by a network of dash-mounted smartphones to work out how far the driver is from the lights and warns the driver when slowing slightly would help them avoid reaching the lights while they are still red.

In the Cambridge tests, researchers calculated that varying their speed to hit the lights at the right time could cut fuel consumption by a whopping 20 percent.

"Cars are responsible for 28 percent of the energy consumption and 32 percent of the carbon dioxide emissions in the United States," said Emmanouil Koukoumidis, a visiting researcher at MIT who led the project.

"If you can save even a small percentage of that, then you can have a large effect on the energy that the U.S. consumes."

Eventually, it's possible that such software could be incorporated into navigation systems and even expanded to provide awareness of other information such as fuel prices, parking spaces or the progress of city buses.

However, for now, it remains strictly a research project -- Koukoumidis believes one of the greatest challenges of a full implementation would be getting the number of drivers required involved to make it a workable solution to congestion.